The head-mounted display is a device that displays images and colors. Usually, it makes a display screen approach the user's eyes in the form of an eye patch or a helmet, and projects screens to the eyes in a short distance by adjusting the focal length through an optical path.
Nowadays, head-mounted displays emerge endlessly like mushrooms after rain. The head-mounted display generally includes a display portion, a head-mounted portion and a sound outputting portion. In the prior art, the head band of the head-mounted portion has a fixed length after the processing, and when being worn, it cannot be extended or shortened by the user according to his head circumference, so the universality is poor. In addition, the two legs of the display portion also have fixed lengths and cannot be adjusted. The sound generator in the sound outputting portion is fixedly connected to the corresponding end of the head-mounted portion, and cannot be rotated. If the user wants to put the head-mounted display into a storage box during traveling, the sides of the sound generators of two sound outputting portions that are contacted with the ears are not located in the same plane, so a large space is occupied and the storage is inconvenient, which cannot satisfy people's demand.